The present invention relates to a method of controlling a vehicle, a vehicle control apparatus, a transmission, and an apparatus for controlling a transmission, and particularly to a method of controlling a vehicle, a vehicle control apparatus, a transmission, and a transmission control apparatus, which are suitable to control the automatic transmission in the vehicle.
A vehicle of a manual transmission type is excellent in fuel economy compared to a vehicle mounting a transmission using a torque converter. However, coordination of the clutch and the accelerator at starting is difficult to be operated. If the coordination of the clutch and the accelerator at starting is not operated well, a large shock is generated at engaging the clutch, or rotation speed of the engine may be rapidly increased when the clutch pressure is insufficient, that is, what is called as a blowing-up phenomenon occurs. Further, when the clutch is suddenly engaged while rotation speed of the engine is insufficient, or when the vehicle is started to run on an uphill, the engine may be stopped, that is, what is called as engine stopping occurs.
In order to solve these problems, a system automatizing clutching and shifting using the mechanism of a manual transmission, that is, an automatized MT (an automatized manual transmission) has been developed. However, a driver sometimes feels incongruity because suspension of driving torque occurs by disengaging and engaging of the clutch in the control at shifting gear in the conventional automatized MT (the automatized manual transmission).
A system disclosed in, for example, U.S. Pat. No. 2,703,169 is known. In order to avoid the interruption of torque during shifting in the system, an assist clutch or a friction clutch of one form of a friction transfer means is added to the conventional automatized MT (the automatized manual transmission) to perform rotation speed synchronization and torque transmission for shifting gear by controlling the assist clutch when shifting is performed.
It is necessary to control the above assist clutch to synchronize the rotation speed of an input shaft of the transmission with the rotation speed which corresponds to the next gear position by the above assist clutch in such a vehicle. However, it was revealed that the time required to synchronize these rotation speeds gets longer in consequence of the change in characteristics due to the machine difference between assist clutches or the deterioration with age, the change in characteristics due to the replacement of the assist clutch or the changing of operating fluid, or the machine difference between engines or the deterioration with age, and shift quality is deteriorated by the sluggish feeling of shifting. Moreover, the striking-feeling occurs if the time required to synchronize the rotation speeds is occasionally shortened, and shift quality decreases.